Alpha blending, or alpha composition, is a common way to create a translucency effect in a resulting destination image by mixing pixels from two different image sources. The alpha value is used to determine how much each source pixel should contribute to the destination pixel. True alpha blending can therefore be expressed asDestination_pixel=source—1_pixel×alpha+source—2_pixel×(1−alpha)  (Equation 1)
The value of alpha could be either constant for the entire image, or the value of alpha could change for each pixel.
When it is desired to create alpha blending effects on the display of an electronic apparatus such as, for instance, a mobile terminal, one option is to implement true alpha blending functionality in hardware. However, hardware implementation has its expenses, and since it can often be expected that alpha blending effects will not be that frequently used, it may not be worth the expense to implement true alpha blending functionality in hardware. If the electronic apparatus lacks such dedicated alpha blending hardware, it can alternatively be done in software. However, a drawback of this is that true alpha blending requires much processing power, particularly if alpha blending is to be performed for sequences of digital images in real-time (such as in the viewfinder of a digital camera, or for a video call). Extensive processing power may not be available, particularly when the electronic apparatus is a miniaturized, portable one (for instance a mobile terminal).
Thus, there is a need for an alternative to performing true alpha blending either in dedicated hardware or in software.